editors/nvi2: Update to V2.2.1

https://github.com/lichray/nvi2/releases/tag/v2.2.1

Changes since V2.2.0:

• Display control chars in altnotation.
• Intuitively jump between troff paragraphs.
• Keep correct count for unprintable character sequences in opts_print().
• Do a full reformat when ^L/^R redrawing.
• Fix printing of line number when the 's' command is used with the 'c' flag and the number option is set.
• Fix wide buffer growth when expanding filenames.
• Fix segmentation fault when window size changes.
• Fix buffer overflow in ex_comm_search.
• Fix segmentation fault in number increment.
• Fix for terminal state corruption on q from ex-mode.
• Fix core dump when tags file pattern has a trailing '\'.

Reported by: Zhihao Yuan